The Tax Cuts and Jobs Act changed the way tax is calculated for most taxpayers, including those with substantial income not subject to withholding.

The newly revised estimated tax package, Form 1040-ES is designed to help taxpayers figure these payments correctly.

A companion publication, Publication 505, Tax Withholding and Estimated Tax, has additional details, including worksheets and examples, that can help taxpayers determine whether they should pay estimated tax, such as those who have dividend or capital gain income, owe alternative minimum tax or have other special situations.

A change in the inflation adjustment calculations for 2018 under the Tax Cuts and Jobs Act, reduced the maximum deductible HSA contribution for taxpayers with family coverage under an HDHP by $50, to $6,850.

For 2018, taxpayers with family coverage under an HDHP may treat $6,900 as the maximum deductible HSA contribution.

Small business owners that offer goods and services online may be part of the sharing economy. Activities such as ride sharing, freelancing, renting a spare bedroom and crowd funding are usually taxable. The IRS has a Sharing Economy Tax Center to help these taxpayers find the information they need to meet their tax obligations.

There is new twist (yes, another new twist!) on an old phone scam as criminals use telephone numbers that mimic IRS Taxpayer Assistance Centers (TACs) to trick taxpayers into paying non-existent tax bills.

In the latest version of the phone scam, criminals claim to be calling from a local IRS TAC office. Scam artists have programmed their computers to display the TAC telephone number, which appears on the taxpayer’s Caller ID when the call is made.

If the taxpayer questions their demand for tax payment, they direct the taxpayer to IRS.gov to look up the local TAC office telephone number to verify the phone number. The crooks hang up, wait a short time and then call back a second time, and they are able to fake or “spoof” the Caller ID to appear to be the IRS office calling. After the taxpayer has “verified” the call number, the fraudsters resume their demands for money, generally demanding payment on a debit card.

Taxpayers who experience tax-related identity theft may wonder when they should file a Form 14039, Identity Theft Affidavit.

In the vast majority of tax-related identity theft cases, there is no need to file the Form 14039 affidavit. The Form 14039 affidavit should be filed if the taxpayer attempts to file an electronic tax return and the IRS rejects it because a return bearing the taxpayer’s Social Security number already has been filed. Or, it should be filed if the IRS instructs the taxpayer to do so.

►EMPLOYERS AND BUSINESS OWNERS:

Business owners: Ensure employees check their withholding

Business owners should remind employees to check their withholding and do a “paycheck checkup” following changes from the Tax Cuts and Jobs Act. Using the Withholding Calculator is the best way for employees to check that they aren’t having too much or too little tax withheld from their paychecks.

The IRS issued guidance that provides relief for certain small employers that wish to claim the Small Business Health Care Tax Credit for 2017 and later years.

In general, the relief provided helps employers who first claim the credit for all or part of 2016 or a later taxable year for coverage offered through a SHOP Marketplace, but don’t have SHOP Marketplace plans available to offer to employees for all or part of the remainder of the credit period because the county where the employer is located has no SHOP Marketplace plans.